Although he's got his own hit musical, Matilda, which opens on Broadway in April, the Perth-born comedian and composer says too shy to tell Andrew Lloyd Webber how keen he was to play Judas in a new arena production of Jesus Christ Superstar.

"I had always wanted to do it, more than I had ever wanted to do any role ever," Minchin says.

"I had lunch with Andrew Lloyd Webber at the end of 2011, because my musical Matilda is in one of the theatres that he owns in London."

"I said I had always wanted to play Judas and he laughed and I kind of laughed as well, because no one ever takes me seriously about anything, ever."

"I went home after that lunch and wrote an email thanking him and saying 'by the way, I was serious about wanting to play Judas' but I didn't have the courage to send it so I put it in my draft box."

"Then I went to New York for opening night of a version of Jesus Christ Superstar on Broadway and it was great but I just sat there and it really reinvigorated my confidence."

"I thought, of all roles, I can do that role. It's a rock voice and I really understand the drama of it."

"The next day I sent the email and I immediately got a reply saying: damn, you should have told me earlier that you were serious about that. We've just cast Seal."

When circumstances changed and Seal had to pull out, Minchin received a call. Even then, he still doubted himself.

"I said 'how do you know I can do it? - you should audition me' and they said ok, fine."

"So I went to this audition that I had demanded and sang Judas' death in front of Lloyd-Webber and the director in this strange kind of conservatory out the back of Lloyd-Webber's company's building and here we are."

The arena production, which also stars Sporty Spice Mel C, starts its Australian tour in Minchin's hometown, Perth, in May.

It's a busy year for Minchin. Matilda opens on Broadway in April, he's appearing in Tom Stoppard's Rosencrantz and Gildenstern Are Dead for the Sydney Theatre Company later this year, he will continue to appear in US Cable TV series Californication.

He's also working on a new musical.

Hear the full and very entertaining interview with Geoff Hutchison via the audio link.